The invention relates to an automatic or semi-automatic solder paste printing machine.
Solder paste printing machines typically comprise a pivoting (clam shell motion) head assembly which carries a separate structure for squeegee motion and guidance. The weight of the head assembly is quite high and the access to the loading area for securing the board and the stencil and introducing solder paste is limited. A top view of the board and stencil when the head assembly is down is not possible without the squeegee structure also down. Direct full board/stencil viewing is obscured by the squeegee structure. Further, access to the tooling area is limited, squeegees cannot be removed easily and the prior art machines are not readily `scaleable`.
The tilt-slide squeegee drive structure of the invention is superior to prior art designs because it moves out from and clear of the service area of the printing system. Other systems open only to a limited degree. The tilt-slide combination allows the operator direct down viewing of critical stencil to board alignment which is not possible on existing designs.
The invention provides for a tilt-slide squeegee drive head which provides for simple stencil alignment, better in process control, such as checking stencil alignment and solder paste quantity and print performance. The invention allows exceptional access to the stencil loading area and simplifies paste replenishing, stencil changes and squeegee cleaning with minimal effort.
The quick release squeegees further enhances the structures ease of use by allowing quick changes of squeegees. Prior apparatus have larger, heavier means for removal, not suited for quick change. Instead of relying on intermediate hardware, the structure of the invention embodies a method of securing squeegees directly to the driving mechanism.
The invention provides a powdered squeegee drive integrated with a tilting and sliding structure which greatly improves the accessibility and ease of setup for solder paste printing machines. An aspect of the invention is guide rails which serve the dual function of guiding and sliding the squeegee head. The hardware is controlled away from service areas.
The tilt-slide design and two parallel rods define the length of the squeegee structure. All the hardware attaches to these rods. Therefore, this tilt-slide head can accommodate varying printer sizes by a simple change in the length of the rods and length of the drive belt.